Edit
thodg/got/lib/diffreg.c
Stefan Sperling
- lib/diffreg.c
-
/* $OpenBSD: diffreg.c,v 1.91 2016/03/01 20:57:35 natano Exp $ */ /* * Copyright (C) Caldera International Inc. 2001-2002. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code and documentation must retain the above * copyright notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed or owned by Caldera * International, Inc. * 4. Neither the name of Caldera International, Inc. nor the names of other * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT, * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)diffreg.c 8.1 (Berkeley) 6/6/93 */ #include <sys/stat.h> #include <sys/wait.h> #include <sys/queue.h> #include <ctype.h> #include <err.h> #include <errno.h> #include <fcntl.h> #include <paths.h> #include <stdarg.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <limits.h> #include <sha1.h> #include <zlib.h> #include "got_error.h" #include "got_object.h" #include "got_diff.h" #include "got_lib_diff.h" #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) /* * diff - compare two files. */ /* * Uses an algorithm due to Harold Stone, which finds * a pair of longest identical subsequences in the two * files. * * The major goal is to generate the match vector J. * J[i] is the index of the line in file1 corresponding * to line i file0. J[i] = 0 if there is no * such line in file1. * * Lines are hashed so as to work in core. All potential * matches are located by sorting the lines of each file * on the hash (called ``value''). In particular, this * collects the equivalence classes in file1 together. * Subroutine equiv replaces the value of each line in * file0 by the index of the first element of its * matching equivalence in (the reordered) file1. * To save space equiv squeezes file1 into a single * array member in which the equivalence classes * are simply concatenated, except that their first * members are flagged by changing sign. * * Next the indices that point into member are unsorted into * array class according to the original order of file0. * * The cleverness lies in routine stone. This marches * through the lines of file0, developing a vector klist * of "k-candidates". At step i a k-candidate is a matched * pair of lines x,y (x in file0 y in file1) such that * there is a common subsequence of length k * between the first i lines of file0 and the first y * lines of file1, but there is no such subsequence for * any smaller y. x is the earliest possible mate to y * that occurs in such a subsequence. * * Whenever any of the members of the equivalence class of * lines in file1 matable to a line in file0 has serial number * less than the y of some k-candidate, that k-candidate * with the smallest such y is replaced. The new * k-candidate is chained (via pred) to the current * k-1 candidate so that the actual subsequence can * be recovered. When a member has serial number greater * that the y of all k-candidates, the klist is extended. * At the end, the longest subsequence is pulled out * and placed in the array J by unravel * * With J in hand, the matches there recorded are * check'ed against reality to assure that no spurious * matches have crept in due to hashing. If they have, * they are broken, and "jackpot" is recorded--a harmless * matter except that a true match for a spuriously * mated line may now be unnecessarily reported as a change. * * Much of the complexity of the program comes simply * from trying to minimize core utilization and * maximize the range of doable problems by dynamically * allocating what is needed and reusing what is not. * The core requirements for problems larger than somewhat * are (in words) 2*length(file0) + length(file1) + * 3*(number of k-candidates installed), typically about * 6n words for files of length n. */ struct cand { int x; int y; int pred; }; struct line { int serial; int value; }; static void diff_output(FILE *, const char *, ...); static int output(FILE *, struct got_diff_changes *, struct got_diff_state *, struct got_diff_args *, const char *, FILE *, const char *, FILE *, int); static void check(struct got_diff_state *, FILE *, FILE *, int); static void uni_range(FILE *, int, int); static void dump_unified_vec(FILE *, struct got_diff_changes *, struct got_diff_state *, struct got_diff_args *, FILE *, FILE *, int); static int prepare(struct got_diff_state *, int, FILE *, off_t, int); static void prune(struct got_diff_state *); static void equiv(struct line *, int, struct line *, int, int *); static void unravel(struct got_diff_state *, int); static int unsort(struct line *, int, int *); static int change(FILE *, struct got_diff_changes *, struct got_diff_state *, struct got_diff_args *, const char *, FILE *, const char *, FILE *, int, int, int, int, int *); static void sort(struct line *, int); static void print_header(FILE *, struct got_diff_state *, struct got_diff_args *, const char *, const char *); static int asciifile(FILE *); static int fetch(FILE *, struct got_diff_state *, struct got_diff_args *, long *, int, int, FILE *, int, int, int); static int newcand(struct got_diff_state *, int, int, int, int *); static int search(struct got_diff_state *, int *, int, int); static int skipline(FILE *); static int isqrt(int); static int stone(struct got_diff_state *, int *, int, int *, int *, int); static int readhash(struct got_diff_state *, FILE *, int); static int files_differ(struct got_diff_state *, FILE *, FILE *, int); static char *match_function(struct got_diff_state *, const long *, int, FILE *); /* * chrtran points to one of 2 translation tables: cup2low if folding upper to * lower case clow2low if not folding case */ u_char clow2low[256] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; u_char cup2low[256] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; static void diff_output(FILE *outfile, const char *fmt, ...) { va_list ap; if (outfile == NULL) return; va_start(ap, fmt); vfprintf(outfile, fmt, ap); va_end(ap); } const struct got_error * got_diffreg(int *rval, FILE *f1, FILE *f2, int flags, struct got_diff_args *args, struct got_diff_state *ds, FILE *outfile, struct got_diff_changes *changes) { const struct got_error *err = NULL; int i, *p; long *lp; *rval = D_SAME; ds->anychange = 0; ds->lastline = 0; ds->lastmatchline = 0; ds->context_vec_ptr = ds->context_vec_start - 1; ds->max_context = GOT_DIFF_MAX_CONTEXT; if (flags & D_IGNORECASE) ds->chrtran = cup2low; else ds->chrtran = clow2low; if (S_ISDIR(ds->stb1.st_mode) != S_ISDIR(ds->stb2.st_mode)) { *rval = (S_ISDIR(ds->stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2); return NULL; } if (flags & D_EMPTY1) { f1 = fopen(_PATH_DEVNULL, "r"); if (f1 == NULL) { err = got_error_from_errno(); goto closem; } } else if (f1 == NULL) { args->status |= 2; goto closem; } if (flags & D_EMPTY2) { f2 = fopen(_PATH_DEVNULL, "r"); if (f2 == NULL) { err = got_error_from_errno(); goto closem; } } else if (f2 == NULL) { args->status |= 2; goto closem; } switch (files_differ(ds, f1, f2, flags)) { case 0: goto closem; case 1: break; default: /* error */ args->status |= 2; goto closem; } if ((flags & D_FORCEASCII) == 0 && (!asciifile(f1) || !asciifile(f2))) { *rval = D_BINARY; args->status |= 1; goto closem; } if (prepare(ds, 0, f1, ds->stb1.st_size, flags)) { err = got_error_from_errno(); goto closem; } if (prepare(ds, 1, f2, ds->stb2.st_size, flags)) { err = got_error_from_errno(); goto closem; } prune(ds); sort(ds->sfile[0], ds->slen[0]); sort(ds->sfile[1], ds->slen[1]); ds->member = (int *)ds->file[1]; equiv(ds->sfile[0], ds->slen[0], ds->sfile[1], ds->slen[1], ds->member); p = reallocarray(ds->member, ds->slen[1] + 2, sizeof(*ds->member)); if (p == NULL) { err = got_error_from_errno(); goto closem; } ds->member = p; ds->class = (int *)ds->file[0]; if (unsort(ds->sfile[0], ds->slen[0], ds->class)) { err = got_error_from_errno(); goto closem; } p = reallocarray(ds->class, ds->slen[0] + 2, sizeof(*ds->class)); if (p == NULL) { err = got_error_from_errno(); goto closem; } ds->class = p; ds->klist = calloc(ds->slen[0] + 2, sizeof(*ds->klist)); if (ds->klist == NULL) { err = got_error_from_errno(); goto closem; } ds->clen = 0; ds->clistlen = 100; ds->clist = calloc(ds->clistlen, sizeof(*ds->clist)); if (ds->clist == NULL) { err = got_error_from_errno(); goto closem; } i = stone(ds, ds->class, ds->slen[0], ds->member, ds->klist, flags); if (i < 0) { err = got_error_from_errno(); goto closem; } p = reallocarray(ds->J, ds->len[0] + 2, sizeof(*ds->J)); if (p == NULL) { err = got_error_from_errno(); goto closem; } ds->J = p; unravel(ds, ds->klist[i]); lp = reallocarray(ds->ixold, ds->len[0] + 2, sizeof(*ds->ixold)); if (lp == NULL) { err = got_error_from_errno(); goto closem; } ds->ixold = lp; lp = reallocarray(ds->ixnew, ds->len[1] + 2, sizeof(*ds->ixnew)); if (lp == NULL) { err = got_error_from_errno(); goto closem; } ds->ixnew = lp; check(ds, f1, f2, flags); if (output(outfile, changes, ds, args, args->label[0], f1, args->label[1], f2, flags)) err = got_error_from_errno(); closem: free(ds->J); free(ds->member); free(ds->class); free(ds->clist); free(ds->klist); free(ds->ixold); free(ds->ixnew); if (ds->anychange) { args->status |= 1; if (*rval == D_SAME) *rval = D_DIFFER; } if (f1 != NULL) fclose(f1); if (f2 != NULL) fclose(f2); return (err); } /* * Check to see if the given files differ. * Returns 0 if they are the same, 1 if different, and -1 on error. * XXX - could use code from cmp(1) [faster] */ static int files_differ(struct got_diff_state *ds, FILE *f1, FILE *f2, int flags) { char buf1[BUFSIZ], buf2[BUFSIZ]; size_t i, j; if ((flags & (D_EMPTY1|D_EMPTY2)) || ds->stb1.st_size != ds->stb2.st_size || (ds->stb1.st_mode & S_IFMT) != (ds->stb2.st_mode & S_IFMT)) return (1); for (;;) { i = fread(buf1, 1, sizeof(buf1), f1); j = fread(buf2, 1, sizeof(buf2), f2); if ((!i && ferror(f1)) || (!j && ferror(f2))) return (-1); if (i != j) return (1); if (i == 0) return (0); if (memcmp(buf1, buf2, i) != 0) return (1); } } static int prepare(struct got_diff_state *ds, int i, FILE *fd, off_t filesize, int flags) { struct line *p, *q; int j, h; size_t sz; rewind(fd); sz = (filesize <= SIZE_MAX ? filesize : SIZE_MAX) / 25; if (sz < 100) sz = 100; p = calloc(sz + 3, sizeof(*p)); if (p == NULL) return (-1); for (j = 0; (h = readhash(ds, fd, flags));) { if (j == sz) { sz = sz * 3 / 2; q = reallocarray(p, sz + 3, sizeof(*p)); if (q == NULL) { free(p); return (-1); } p = q; } p[++j].value = h; } ds->len[i] = j; ds->file[i] = p; return (0); } static void prune(struct got_diff_state *ds) { int i, j; for (ds->pref = 0; ds->pref < ds->len[0] && ds->pref < ds->len[1] && ds->file[0][ds->pref + 1].value == ds->file[1][ds->pref + 1].value; ds->pref++) ; for (ds->suff = 0; ds->suff < ds->len[0] - ds->pref && ds->suff < ds->len[1] - ds->pref && ds->file[0][ds->len[0] - ds->suff].value == ds->file[1][ds->len[1] - ds->suff].value; ds->suff++) ; for (j = 0; j < 2; j++) { ds->sfile[j] = ds->file[j] + ds->pref; ds->slen[j] = ds->len[j] - ds->pref - ds->suff; for (i = 0; i <= ds->slen[j]; i++) ds->sfile[j][i].serial = i; } } static void equiv(struct line *a, int n, struct line *b, int m, int *c) { int i, j; i = j = 1; while (i <= n && j <= m) { if (a[i].value < b[j].value) a[i++].value = 0; else if (a[i].value == b[j].value) a[i++].value = j; else j++; } while (i <= n) a[i++].value = 0; b[m + 1].value = 0; j = 0; while (++j <= m) { c[j] = -b[j].serial; while (b[j + 1].value == b[j].value) { j++; c[j] = b[j].serial; } } c[j] = -1; } /* Code taken from ping.c */ static int isqrt(int n) { int y, x = 1; if (n == 0) return (0); do { /* newton was a stinker */ y = x; x = n / x; x += y; x /= 2; } while ((x - y) > 1 || (x - y) < -1); return (x); } static int stone(struct got_diff_state *ds, int *a, int n, int *b, int *c, int flags) { int i, k, y, j, l; int oldc, tc, oldl, sq; u_int numtries, bound; int error; if (flags & D_MINIMAL) bound = UINT_MAX; else { sq = isqrt(n); bound = MAXIMUM(256, sq); } k = 0; c[0] = newcand(ds, 0, 0, 0, &error); if (error) return -1; for (i = 1; i <= n; i++) { j = a[i]; if (j == 0) continue; y = -b[j]; oldl = 0; oldc = c[0]; numtries = 0; do { if (y <= ds->clist[oldc].y) continue; l = search(ds, c, k, y); if (l != oldl + 1) oldc = c[l - 1]; if (l <= k) { if (ds->clist[c[l]].y <= y) continue; tc = c[l]; c[l] = newcand(ds, i, y, oldc, &error); if (error) return -1; oldc = tc; oldl = l; numtries++; } else { c[l] = newcand(ds, i, y, oldc, &error); if (error) return -1; k++; break; } } while ((y = b[++j]) > 0 && numtries < bound); } return (k); } static int newcand(struct got_diff_state *ds, int x, int y, int pred, int *errorp) { struct cand *q; if (ds->clen == ds->clistlen) { ds->clistlen = ds->clistlen * 11 / 10; q = reallocarray(ds->clist, ds->clistlen, sizeof(*ds->clist)); if (q == NULL) { *errorp = -1; free(ds->clist); ds->clist = NULL; return 0; } ds->clist = q; } q = ds->clist + ds->clen; q->x = x; q->y = y; q->pred = pred; *errorp = 0; return (ds->clen++); } static int search(struct got_diff_state *ds, int *c, int k, int y) { int i, j, l, t; if (ds->clist[c[k]].y < y) /* quick look for typical case */ return (k + 1); i = 0; j = k + 1; for (;;) { l = (i + j) / 2; if (l <= i) break; t = ds->clist[c[l]].y; if (t > y) j = l; else if (t < y) i = l; else return (l); } return (l + 1); } static void unravel(struct got_diff_state *ds, int p) { struct cand *q; int i; for (i = 0; i <= ds->len[0]; i++) ds->J[i] = i <= ds->pref ? i : i > ds->len[0] - ds->suff ? i + ds->len[1] - ds->len[0] : 0; for (q = ds->clist + p; q->y != 0; q = ds->clist + q->pred) ds->J[q->x + ds->pref] = q->y + ds->pref; } /* * Check does double duty: * 1. ferret out any fortuitous correspondences due * to confounding by hashing (which result in "jackpot") * 2. collect random access indexes to the two files */ static void check(struct got_diff_state *ds, FILE *f1, FILE *f2, int flags) { int i, j, jackpot, c, d; long ctold, ctnew; rewind(f1); rewind(f2); j = 1; ds->ixold[0] = ds->ixnew[0] = 0; jackpot = 0; ctold = ctnew = 0; for (i = 1; i <= ds->len[0]; i++) { if (ds->J[i] == 0) { ds->ixold[i] = ctold += skipline(f1); continue; } while (j < ds->J[i]) { ds->ixnew[j] = ctnew += skipline(f2); j++; } if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS|D_IGNORECASE)) { for (;;) { c = getc(f1); d = getc(f2); /* * GNU diff ignores a missing newline * in one file for -b or -w. */ if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) { if (c == EOF && d == '\n') { ctnew++; break; } else if (c == '\n' && d == EOF) { ctold++; break; } } ctold++; ctnew++; if ((flags & D_FOLDBLANKS) && isspace(c) && isspace(d)) { do { if (c == '\n') break; ctold++; } while (isspace(c = getc(f1))); do { if (d == '\n') break; ctnew++; } while (isspace(d = getc(f2))); } else if ((flags & D_IGNOREBLANKS)) { while (isspace(c) && c != '\n') { c = getc(f1); ctold++; } while (isspace(d) && d != '\n') { d = getc(f2); ctnew++; } } if (ds->chrtran[c] != ds->chrtran[d]) { jackpot++; ds->J[i] = 0; if (c != '\n' && c != EOF) ctold += skipline(f1); if (d != '\n' && c != EOF) ctnew += skipline(f2); break; } if (c == '\n' || c == EOF) break; } } else { for (;;) { ctold++; ctnew++; if ((c = getc(f1)) != (d = getc(f2))) { /* jackpot++; */ ds->J[i] = 0; if (c != '\n' && c != EOF) ctold += skipline(f1); if (d != '\n' && c != EOF) ctnew += skipline(f2); break; } if (c == '\n' || c == EOF) break; } } ds->ixold[i] = ctold; ds->ixnew[j] = ctnew; j++; } for (; j <= ds->len[1]; j++) ds->ixnew[j] = ctnew += skipline(f2); /* * if (jackpot) * fprintf(stderr, "jackpot\n"); */ } /* shellsort CACM #201 */ static void sort(struct line *a, int n) { struct line *ai, *aim, w; int j, m = 0, k; if (n == 0) return; for (j = 1; j <= n; j *= 2) m = 2 * j - 1; for (m /= 2; m != 0; m /= 2) { k = n - m; for (j = 1; j <= k; j++) { for (ai = &a[j]; ai > a; ai -= m) { aim = &ai[m]; if (aim < ai) break; /* wraparound */ if (aim->value > ai[0].value || (aim->value == ai[0].value && aim->serial > ai[0].serial)) break; w.value = ai[0].value; ai[0].value = aim->value; aim->value = w.value; w.serial = ai[0].serial; ai[0].serial = aim->serial; aim->serial = w.serial; } } } } static int unsort(struct line *f, int l, int *b) { int *a, i; a = calloc(l + 1, sizeof(*a)); if (a == NULL) return (-1); for (i = 1; i <= l; i++) a[f[i].serial] = f[i].value; for (i = 1; i <= l; i++) b[i] = a[i]; free(a); return (0); } static int skipline(FILE *f) { int i, c; for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++) continue; return (i); } static int output(FILE *outfile, struct got_diff_changes *changes, struct got_diff_state *ds, struct got_diff_args *args, const char *file1, FILE *f1, const char *file2, FILE *f2, int flags) { int m, i0, i1, j0, j1; int error = 0; rewind(f1); rewind(f2); m = ds->len[0]; ds->J[0] = 0; ds->J[m + 1] = ds->len[1] + 1; for (i0 = 1; i0 <= m; i0 = i1 + 1) { while (i0 <= m && ds->J[i0] == ds->J[i0 - 1] + 1) i0++; j0 = ds->J[i0 - 1] + 1; i1 = i0 - 1; while (i1 < m && ds->J[i1 + 1] == 0) i1++; j1 = ds->J[i1 + 1] - 1; ds->J[i1] = j1; error = change(outfile, changes, ds, args, file1, f1, file2, f2, i0, i1, j0, j1, &flags); if (error) return (error); } if (m == 0) { error = change(outfile, changes, ds, args, file1, f1, file2, f2, 1, 0, 1, ds->len[1], &flags); if (error) return (error); } if (ds->anychange != 0) dump_unified_vec(outfile, changes, ds, args, f1, f2, flags); return (0); } static void uni_range(FILE *outfile, int a, int b) { if (a < b) diff_output(outfile, "%d,%d", a, b - a + 1); else if (a == b) diff_output(outfile, "%d", b); else diff_output(outfile, "%d,0", b); } /* * Indicate that there is a difference between lines a and b of the from file * to get to lines c to d of the to file. If a is greater then b then there * are no lines in the from file involved and this means that there were * lines appended (beginning at b). If c is greater than d then there are * lines missing from the to file. */ static int change(FILE *outfile, struct got_diff_changes *changes, struct got_diff_state *ds, struct got_diff_args *args, const char *file1, FILE *f1, const char *file2, FILE *f2, int a, int b, int c, int d, int *pflags) { int i; if (a > b && c > d) return (0); if (*pflags & D_HEADER) { diff_output(outfile, "%s %s %s\n", args->diffargs, file1, file2); *pflags &= ~D_HEADER; } if (args->diff_format == D_UNIFIED) { /* * Allocate change records as needed. */ if (ds->context_vec_ptr == ds->context_vec_end - 1) { struct context_vec *cvp; ptrdiff_t offset; offset = ds->context_vec_ptr - ds->context_vec_start; ds->max_context <<= 1; ds->context_vec_start = cvp = reallocarray(ds->context_vec_start, ds->max_context, sizeof(*ds->context_vec_start)); if (cvp == NULL) { free(ds->context_vec_start); return (-1); } ds->context_vec_start = cvp; ds->context_vec_end = ds->context_vec_start + ds->max_context; ds->context_vec_ptr = ds->context_vec_start + offset; } if (ds->anychange == 0) { /* * Print the context/unidiff header first time through. */ print_header(outfile, ds, args, file1, file2); ds->anychange = 1; } else if (a > ds->context_vec_ptr->b + (2 * args->diff_context) + 1 && c > ds->context_vec_ptr->d + (2 * args->diff_context) + 1) { /* * If this change is more than 'diff_context' lines from the * previous change, dump the record and reset it. */ dump_unified_vec(outfile, changes, ds, args, f1, f2, *pflags); } ds->context_vec_ptr++; ds->context_vec_ptr->a = a; ds->context_vec_ptr->b = b; ds->context_vec_ptr->c = c; ds->context_vec_ptr->d = d; return (0); } if (ds->anychange == 0) ds->anychange = 1; if (args->diff_format == D_BRIEF) return (0); i = fetch(outfile, ds, args, ds->ixnew, c, d, f2, '\0', 0, *pflags); return (0); } static int fetch(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args, long *f, int a, int b, FILE *lb, int ch, int oldfile, int flags) { int i, j, c, lastc, col, nc; if (a > b) return (0); for (i = a; i <= b; i++) { fseek(lb, f[i - 1], SEEK_SET); nc = f[i] - f[i - 1]; if (ch != '\0') { diff_output(outfile, "%c", ch); if (args->Tflag && args->diff_format == D_UNIFIED) diff_output(outfile, "\t"); else if (args->diff_format != D_UNIFIED) diff_output(outfile, " "); } col = 0; for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) { if ((c = getc(lb)) == EOF) { diff_output(outfile, "\n\\ No newline at end of " "file\n"); return (0); } if (c == '\t' && (flags & D_EXPANDTABS)) { do { diff_output(outfile, " "); } while (++col & 7); } else { diff_output(outfile, "%c", c); col++; } } } return (0); } /* * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578. */ static int readhash(struct got_diff_state *ds, FILE *f, int flags) { int i, t, space; int sum; sum = 1; space = 0; if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) == 0) { if (flags & D_IGNORECASE) for (i = 0; (t = getc(f)) != '\n'; i++) { if (t == EOF) { if (i == 0) return (0); break; } sum = sum * 127 + ds->chrtran[t]; } else for (i = 0; (t = getc(f)) != '\n'; i++) { if (t == EOF) { if (i == 0) return (0); break; } sum = sum * 127 + t; } } else { for (i = 0;;) { switch (t = getc(f)) { case '\t': case '\r': case '\v': case '\f': case ' ': space++; continue; default: if (space && (flags & D_IGNOREBLANKS) == 0) { i++; space = 0; } sum = sum * 127 + ds->chrtran[t]; i++; continue; case EOF: if (i == 0) return (0); /* FALLTHROUGH */ case '\n': break; } break; } } /* * There is a remote possibility that we end up with a zero sum. * Zero is used as an EOF marker, so return 1 instead. */ return (sum == 0 ? 1 : sum); } static int asciifile(FILE *f) { unsigned char buf[BUFSIZ]; size_t cnt; if (f == NULL) return (1); rewind(f); cnt = fread(buf, 1, sizeof(buf), f); return (memchr(buf, '\0', cnt) == NULL); } #define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0) static char * match_function(struct got_diff_state *ds, const long *f, int pos, FILE *fp) { unsigned char buf[FUNCTION_CONTEXT_SIZE]; size_t nc; int last = ds->lastline; char *state = NULL; ds->lastline = pos; while (pos > last) { fseek(fp, f[pos - 1], SEEK_SET); nc = f[pos] - f[pos - 1]; if (nc >= sizeof(buf)) nc = sizeof(buf) - 1; nc = fread(buf, 1, nc, fp); if (nc > 0) { buf[nc] = '\0'; buf[strcspn(buf, "\n")] = '\0'; if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') { if (begins_with(buf, "private:")) { if (!state) state = " (private)"; } else if (begins_with(buf, "protected:")) { if (!state) state = " (protected)"; } else if (begins_with(buf, "public:")) { if (!state) state = " (public)"; } else { strlcpy(ds->lastbuf, buf, sizeof ds->lastbuf); if (state) strlcat(ds->lastbuf, state, sizeof ds->lastbuf); ds->lastmatchline = pos; return ds->lastbuf; } } } pos--; } return ds->lastmatchline > 0 ? ds->lastbuf : NULL; } /* dump accumulated "unified" diff changes */ static void dump_unified_vec(FILE *outfile, struct got_diff_changes *changes, struct got_diff_state *ds, struct got_diff_args *args, FILE *f1, FILE *f2, int flags) { struct context_vec *cvp = ds->context_vec_start; int lowa, upb, lowc, upd; int a, b, c, d; char ch, *f; if (ds->context_vec_start > ds->context_vec_ptr) return; b = d = 0; /* gcc */ lowa = MAXIMUM(1, cvp->a - args->diff_context); upb = MINIMUM(ds->len[0], ds->context_vec_ptr->b + args->diff_context); lowc = MAXIMUM(1, cvp->c - args->diff_context); upd = MINIMUM(ds->len[1], ds->context_vec_ptr->d + args->diff_context); diff_output(outfile, "@@ -"); uni_range(outfile, lowa, upb); diff_output(outfile, " +"); uni_range(outfile, lowc, upd); diff_output(outfile, " @@"); if ((flags & D_PROTOTYPE)) { f = match_function(ds, ds->ixold, lowa-1, f1); if (f != NULL) diff_output(outfile, " %s", f); } diff_output(outfile, "\n"); /* * Output changes in "unified" diff format--the old and new lines * are printed together. */ for (; cvp <= ds->context_vec_ptr; cvp++) { if (changes) { struct got_diff_change *change; change = calloc(1, sizeof(*change)); if (change) { memcpy(&change->cv, cvp, sizeof(change->cv)); SIMPLEQ_INSERT_TAIL(&changes->entries, change, entry); changes->nchanges++; } } a = cvp->a; b = cvp->b; c = cvp->c; d = cvp->d; /* * c: both new and old changes * d: only changes in the old file * a: only changes in the new file */ if (a <= b && c <= d) ch = 'c'; else ch = (a <= b) ? 'd' : 'a'; switch (ch) { case 'c': fetch(outfile, ds, args, ds->ixold, lowa, a - 1, f1, ' ', 0, flags); fetch(outfile, ds, args, ds->ixold, a, b, f1, '-', 0, flags); fetch(outfile, ds, args, ds->ixnew, c, d, f2, '+', 0, flags); break; case 'd': fetch(outfile, ds, args, ds->ixold, lowa, a - 1, f1, ' ', 0, flags); fetch(outfile, ds, args, ds->ixold, a, b, f1, '-', 0, flags); break; case 'a': fetch(outfile, ds, args, ds->ixnew, lowc, c - 1, f2, ' ', 0, flags); fetch(outfile, ds, args, ds->ixnew, c, d, f2, '+', 0, flags); break; } lowa = b + 1; lowc = d + 1; } fetch(outfile, ds, args, ds->ixnew, d + 1, upd, f2, ' ', 0, flags); ds->context_vec_ptr = ds->context_vec_start - 1; } static void print_header(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args, const char *file1, const char *file2) { if (args->label[0] != NULL) diff_output(outfile, "--- %s\n", args->label[0]); else diff_output(outfile, "--- %s\t%s", file1, ctime(&ds->stb1.st_mtime)); if (args->label[1] != NULL) diff_output(outfile, "+++ %s\n", args->label[1]); else diff_output(outfile, "+++ %s\t%s", file2, ctime(&ds->stb2.st_mtime)); }